Patent GB-1428212-A (GB)
Title: Atmosphere circulation system
IPC: F04D29/64
Filed: 1973-03-07
Abstract: 1428212 Food treatment apparatus JULIAN ENG CO 7 March 1973 10980/73 Heading A2D [Also in Divisions Fl and F4] An atmosphere circulation system comprises fans each having a rotatable blade disposed within the chamber, at least some of the fans being mounted adjacent substantially opposed portions of the chamber for movement relative to the chamber along a predetermined path substantially transverse to the axis of rotation of the fan blade, and power means for reciprocably moving each fan along its predetermined path and thereby altering the turbulent movement of the atmosphere produced by the opposed flows of the fans. Food such as sausages, ham and bacon is loaded into a chamber 10, Fig. 1, on carts or racks 12 and treated with smoke from a smoke generator 42. A gas burner 38 for heating the chamber 10 has a tube 40 extending substantially the length of the chamber. A humidifier includes a pipe 50. An exhaust duct 48 is provided with manually or automatically operated dampers. The atmosphere in the chamber is circulated by fans 60. Each fan and its driving motor 78, Figs. 3 and 5, are mounted on a carriage 62 which is slidable in vertical tracks 70, 72 within a vertical trunk 64 in one of the lateral walls 16, 18 of the chamber 10. Rollers may be provided between the carriage 62 and the tracks 70, 72. Pairs of fans 60a, 60b which are located either next to one another on the same lateral wall 16 or 18 as shown or opposite one another on opposite lateral walls have their carriages 62 interconnected by a chain 100 passing over an idler sprocket 102 and a driver sprocket 98, the latter being driven by a motor 96 so that the two fans are alternately raised and lowered in opposite phase to one another, the motor being reversed by limit switch(es) at the end of the fan travel. The movements of all or several pairs of fans may be synchronised. An additional chain, opposite to the chain 100 and passing over idler sprockets, may be provided to ensure positive drive in the downward direction. To protect the motors 78 from the atmosphere within the chamber, each trunk 64 is closed by rubber or neoprene flaps 84, 86 which touch each other except where they are parted by the fan shaft 76. Fresh air is supplied to the chamber 10 by means of blowers 92, 94 each connected via a manifold 88 or 90 to a row of trunks 64. The air passes from the trunks to the chamber 10 by leakage through the flaps 84, 86. Current is supplied to each fan motor 78 either through a flexible cable or through a contact shoe sliding along parallel bus bars. A guard screen 114 may be provided in front of each fan, and a rail 116 may be provided to protect the screens and fans from the oarts or racks 12. The fans may move in a horizontal or other non-vertical direction or in an arcuate path. Reciprocation may be achieved by a non-reversing endless chain. If the chamber is used for treating foods without smoke and at ambient temperatures or with refrigerated air, the trunks 64 for isolating the motors 78 from the atmosphere may be omitted. The trunks 64 may also be omitted if the electric motors are replaced by hydraulic motors, Figs. 6-9 (not shown). In Figs. 6-9, a pair of fans moving vertically on opposite walls of the chamber and a third fan moving horizontally along the ceiling are linked by chains and cable to move in unison.